Why do people always blame aliens?
Because people will think they are crazy if they say Gods, angels or spirits.
Aliens are The New Hope for the scientifically wacked.
They blame Aliens for the Pyramids, too... humans just can't cut stone that precisely on their own.
Though I wouldn't rule out suggestions from spirits or wise old Imhotep from beyond the grave.
I think Atlantis (or something like it) did exist, but I think like any story, the details got more rediculous as time went on. Hey, they found Troy, and for years reasonable people thought it was merely mythical.
If you say Mu or Lemuria I swear I'll commit digital homicide.
Personally, that rediculous stuff probably happened on the spirit plane or something like that.